Do you recall our “Photo of the Day” from seven months ago…
Here’s something to look forward to in the new year. The good citizens of East Donegal Township in Lancaster County have partnered with Alliance for the Chesapeake Bay to establish an extensive wildflower meadow on what had been a mowed field of turf grass at Riverside Park in the Susquehanna floodplain near Marietta. As the photo shows, the lawn plants have been eliminated in preparation for seeding with a diverse assortment of native grasses and wildflowers to provide habitat for birds and pollinators including butterflies, bees, and other insects. Once established, the meadow’s extensive vegetative growth will help reduce stormwater runoff by better infiltrating rainfall to recharge the aquifer. During flood events, the plantings will provide soil stabilization and increase the ability of the acreage to uptake nutrients, thus reducing the negative impact of major storms on the quality of water in the river and in Chesapeake Bay. Check the project’s progress by stopping by from time to time in 2024!
Well, here’s what that site looks like today…
The wildflowers, thousands of them, are now in bloom!Black-eyed Susan and Blue Vervain (Verbena hastata) dominate the assortment currently in flower.
And there are pollinating insects galore, most notably butterflies…
A Cabbage White collecting nectar on Blue Vervain.A Clouded or Orange Sulphur among the grasses in the meadow.A Silver-spotted Skipper.The Least Skipper is our tiniest butterfly.The Little Glassywing (Vernia verna), this one feeding on vervain nectar, deposits its eggs on Purpletop grass, which then functions as the host plant for this butterfly’s larvae.A Summer Azure (Celastrina neglecta) feeding on the nectar of a Black-eyed Susan.A Common Buckeye on a “Gloriosa Daisy”, a showy, large-flowered cultivar of Black-eyed Susan.A Red-winged Blackbird with a caterpillar found among the meadow’s lush growth.An Eastern Tiger Swallowtail on Blue Vervain. Nearby Yellow (Tulip) Poplars and other trees serve as host plants for this butterfly’s larvae.The black morph of the Eastern Tiger Swallowtail shows subdued shading in the wings that closely resembles the brilliant color patterns of the more familiar yellow form.The Sachem, this one visiting a Black-eyed Susan, is a variable species with a range that normally lies south of the 40th parallel, the line of latitude that intersects the Susquehanna in the area of the Conejohela Flats at Washington Boro.A Sachem visiting the blooms of Oxeye sunflower. During recent weeks, scorching winds from the south and southwest have transported an abundance of these vagrant skippers into the lower Susquehanna valley and beyond.A male Sachem approaching the bloom of a “Gloriosa Daisy”. Miles north of the 40th parallel, wandering Sachems are currently the most numerous of the butterflies at the Riverfront Park wildflower meadow.Here and there among the meadow’s plantings we noticed one of our favorites starting to flower, the Partridge Pea.Partridge Pea happens to be a host plant for another vagrant from the south, the big, lime-yellow Cloudless Sulphur. We saw at least half a dozen patrolling the meadow.The stars of the show are the Zebra Swallowtails, gorgeous butterflies that rely on stands of native Common Paw-paw trees in the river floodplain to host their eggs and larvae.The red-white-and-blue underside of a Zebra Swallowtail.WOW!
Why on earth would anyone waste their time, energy, and money mowing grass when they could have this? Won’t you please consider committing graminicide this fall? That’s right, kill that lawn—at least the majority of it. Then visit the Ernst Seed website, buy some “Native Northeast Wildlflower Mix” and/or other blends, and get your meadow planted in time for the 2025 growing season. Just think of all the new kinds of native plants and animals you’ll be seeing. It could change your life as well as theirs.
A Snowberry Clearwing (Hemaris diffinis), more commonly known as a hummingbird moth, visits the flowers of Blue Vervain in the Riverfront Park wildflower meadow.
Similar in appearance to the invasive Brown Marmorated Stink Bug, the Western Conifer Seed Bug (Leptoglossus occidentalis) is a seldom-noticed denizen of pines. During the 1950s, their range started expanding from the American west into the eastern states. Like the stink bug, the Western Conifer Seed Bug emits a buzzing sound in flight and is capable of releasing a nasty-smelling compound from scent glands when harassed. They feed on sap from developing pine cones, often causing deformities to the seeds, but posing no real harm to the trees. The Western Conifer Seed Bug causes greatest consternation during the fall when, like the invasive stink bugs, it gathers in numbers and attempts to enter homes to spend the winter. Those that get inside are mostly just an annoyance, but there have been reports of plumbing leaks caused by individual insects piercing PEX plastic water tubing with their mouths.
Where does all the time go? Already in 2024, half the calendar is in the trash and the gasoline and gunpowder gang’s biggest holiday of the year is upon us. Instead of bringing you the memory-making odors of quick-burning sulfur or the noise and multi-faceted irritations that revved-up combustion engines bring, we thought it best to provide our readers with a taste of history for this Fourth of July. Join us, won’t you, for a look back at one of the many events that shaped the landscape of our present-day world.
The early morning’s sun had just begun bathing the verdant gardens of the olde towne centre with a warm glowing light. Birds were singing and the local folk were beginning to stir in preparation for their day’s chores. Then, suddenly, something was stirring afoot.
The great battle had commenced. Within minutes, thousands of colonists spilled onto the pavement to join the melee and defend their homes.
There’s no towne crier spreading the word on horseback. Sensing aggression from a neighboring colony, a worker Pavement Ant (Tetramorium immigrans) functioning as a sentry issues the alert. The aroma of pheromones produced by the sentry warns of danger and calls other workers to drop what their doing and instead respond to defend the nest.Engaged in a dispute over territory, two colonies of Pavement Ants clash. Though native to Europe, there is no evidence of Napoleonic tactics in their warfare. All maneuver seems to be by chance.The workers doing the fighting are the sterile daughters of the one queen in each colony. In addition to defending the nest, they do all the foraging and care for the queen’s eggs and young. The young in each nest are its workers’ sisters and will include one or more new fertile queens. These new queens, along with fertile males (brothers of the workers), develop wings and fly away to mate. After mating, a young queen begins a new colony, excavating her own nest wherein she raises a first brood of workers to tend her forthcoming generation of eggs and young. As the new colony grows, the queen’s workers expand the size of the underground nest by carrying particles of soil to the surface, depositing them around the entrance as telltale mounds.A winged male Pavement Ant gets caught in the fury of combat. His primary role in life is to make a nuptial flight and mate with a queen to start a new colony.
The fighting was at close quarters—face to face with dominant soldiers sparing no effort to prevail in the struggle.
Worker Pavement Ants, all females, assume the role of soldiers to defend their nest, their colony, and their queen.
After about an hour had passed, the tide had turned and the fighting mass drifted to the south of the battle’s starting point. The aggressors had been repelled. The dispute was resolved—at least for a little while.
Thousands of Pavement Ants at the high-water mark of their desperate struggle. It was a fierce, jaw-to-jaw contest to tear one’s opponent to pieces.A winged Pavement Ant, probably a male and not a queen, falls victim to the fighting (upper right). This casualty will not take part in a nuptial flight and will not contribute its colony’s DNA to a new population of ants.The tide turns and the invaders from the south are pushed back in the direction from whence they came. Within minutes, the soldiers transitioned back to being workers. No visual signs of the fight remained; casualties were carried away.
It wasn’t a struggle for independence. And it wasn’t a fight for liberty. For the sterile Pavement Ant worker, all the exertion and all the hazard of assuming the role of a soldier had but one purpose—to raise her sisters and become an aunt. Long live the queen.
Love is in the Air- The conspicuously large Clubbed Mydas Fly (Mydas clavatus) is a harmless mimic of the spider wasps (Pompilidae). They carry their masquerade to the extreme with bold behavior that includes pumping of their abdomen to simulate an ability to sting. Adults visit flowers to feed on pollen and nectar while the larvae are predatory, relying on a diet of scarab beetles (Scarabaeidae) which they find crawling within the dead and rotting wood where they reside. When mating, adults fly around in copula, reminding one of “love bugs” and other members of the fly family Bibionidae, the march flies. This mating pair was photographed along the Susquehanna at Conewago Falls.
Check out these glistening gems—mating damselflies on a late spring afternoon.
It’s two pairs of Powdered Dancers, males clasping ovipositing females, a striped blue form female on the left and a brown form female on the right.A male Stream Bluet (Enallagma exsulans) perched on a grass stem in a vegetated buffer along a rehabilitated creek.A pair of Stream Bluets, male clasping female.A male Ebony Jewelwing (Calopteryx maculata) looking for a mate.There she is, the shy female Ebony Jewelwing among the shelter of some streamside foliage.A male Variable Dancer (Argia fumipennis).A mating pair of Variable Dancers, male clasping female.Two mating pairs of Variable Dancers, males clasping ovipositing females.Two pairs of mating damselflies, Powdered Dancers (left) and Variable Dancers (right), with both females ovipositing.A male Double-striped Bluet (Enallagma basidens) showing his stuff.A female Fragile Forktail.Mating Powdered Dancers, male clasping female, and an ovipositing female Fragile Forktail.A pair of mating Orange Bluets (Enallagma signatum) in wheel position, male above and female below.
Aren’t they precious? You bet they are.
To see these and other damselflies, as well as their larger cousins the dragonflies, be certain to visit your favorite vegetated lake, pond, stream, or wetland on a sunny afternoon. You might be surprised by the variety of colorful species you can find.
And to help identify your sightings, don’t forget to visit our “Damselflies and Dragonflies” page by clicking the tab bearing that name at the top of this page.
The minuscule Long-legged Fly (Condylostylus species) is a predatory consumer of soft-bodied invertebrates. In the headquarters garden, we found this individual and others scurrying around on the leaves of Common Milkweed where they may be seeking to gobble up infesting aphids.
Even in flight, the Twelve-spotted Skimmer is easily identified by the conspicuous color pattern in its wings. Look for it now around vegetated ponds and lakes. Later, during late summer and early fall, this widespread species can often be seen among southbound movements of other migratory dragonflies.
As the month of June gets underway, we spotted this male March Fly (Bibio species) visiting the susquehannawildlife.net headquarters garden.And we found this Great Brown Drake (Hexagenia bilineata), a large species of burrowing mayfly, clinging to our building’s masonry wall after last night’s early June nuptial flight.So when can we expect to see Green June Bugs (Cotinis nitida) devouring our discarded watermelon rinds? Probably not until July.
During one of the interludes between yesterday’s series of thunderstorms and rain showers, we had a chance to visit a wooded picnic spot to devour a little snack. Having packed lite fare, there wasn’t enough to share. Fortunately, pest control wasn’t a concern. It was handled for us…
This young American Toad (Anaxyrus americanus) patrolled the grounds of the grove gobbling up any creepy crawlies it happened to encounter.Though spotted nearby, none of these traditional picnic crashers, possibly Big-headed Ants (Pheidole species), made it through the toad’s dragnet.What had this Eastern Black Carpenter Ant (Camponotus pennsylvanicus) so frustrated during its attempt to spoil our affair?The recycled plastic lumber picnic table left this party pooper with nothing to chew……so it’s back to gnawing on this rotting stump for you!We spied this curious little Crab Spider (Tmarus species) searching the benches for tiny invertebrates.Then, at the corner of the table, we found this Running Crab Spider (Philodromus species) clutching what appeared to be two ofttimes pesky, but harmless, flying insects called non-biting midges (Chironomidae).Down the hatch! Though smaller than your pinky fingernail, the Running Crab Spider is still an accomplished predator.
After enjoying our little luncheon and watching all the sideshows, it was time to cautiously make our way home,…
…halting briefly to allow this Snapping Turtle a chance to cross the road.
During recent weeks, as temperatures have warmed into the 70s and 80s, early season odonates—damselflies and dragonflies—have taken to the wing along our watercourses and wetlands to prey upon small flying insects.
In addition to wetlands, many vegetated streams, ponds, lakes, and rivers are prime locations to find a variety of damselflies and dragonflies.A male Common Whitetail (top) and some Eastern Amberwings (Perithemis tenera) patrol the edge of a verdant pond in search of small flying insects. In addition to defending territories for hunting, many males will begin chasing off potential rivals as the breeding season gets underway. Both of these dragonflies are tolerant of mud-bottomed waters during their aquatic larval stages of life and may be the only species found at places like farm ponds.The Fragile Forktail is common throughout the Lower Susquehanna River Watershed. It is the most likely damselfly to colonize garden ponds, wet ditches, and other small bodies of water.Having just mated with the male seen in the previous image, this female Fragile Forktail prepares to oviposit (lay her eggs) among the submerged plant matter in the shallows of this pond. After hatching, the larval damselflies will spend an entire year as aquatic predators before taking flight as adults next spring.The Blue Dasher is a common dragonfly around streams, ponds, and wetlands. It can frequently be found perched in sunny woodland clearings, even those quite a distance from their breeding area.The Eastern Forktail (Ischnura verticalis) is a common damselfly around almost any calm, vegetated waters. They frequently perch on emergent plant leaves and stems.The Common Baskettail (Epitheca cynosura) is currently numerous around tree-lined pond and lake shores. They spend nearly all of their time on the wing and frequently dart in and out of the shade while hunting and defending their territory from other dragonflies. Unless you happen to catch a quick glimpse of them in good sunlight, these hyperactive insects will appear completely black in color.Another Common Baskettail, this one mostly lacking any black coloration on the base section of the hindwings.The Lancet Clubtail is a handsome early season dragonfly of slow clear streams, ponds, and wetlands. They spend much of their time perched, watching for prey.We found this Lancet Clubtail about 100 yards from a mountain stream perched on the ground atop some debris on a seldom-traveled forest road,……and this one clinging to some shrubs along the shore of a clear woodland pond.
If you’re out and about in coming days, you’ll find that flights of Common Green Darners, Black Saddlebags, and other species are underway as well. As the waters of the lower Susquehanna valley continue to warm, an even greater variety of these insects will take to the wing. To help with the identification of those you see, be certain to click the “Damselflies and Dragonflies” tab at the top of this page.
During the past week, we’ve been exploring wooded slopes around the lower Susquehanna region in search of recently arrived Neotropical birds—particularly those migrants that are singing on breeding territories and will stay to nest. Coincidentally, we noticed a good diversity of species in areas where tent caterpillar nests were apparent.
The conspicuous nest of the Eastern Tent Caterpillar (Malacosoma americanum), a native species of moth. The first instar of the larval caterpillars hatch in early spring from egg masses laid on the limbs of the host tree by an adult female moth during the previous spring. Soon after they begin feeding on the host tree’s first tender shoots, these tiny, seldom-noticed larvae start communal construction of a silk tent to act as a shelter and greenhouse-like solar collector that will both provide protection from the elements and expedite their growth.The familiar last instar of the Eastern Tent Caterpillar is the most consumptive stage of the animal’s life. After feeding in the treetops, they will descend to the ground and seek a sheltered location to pupate. Adult moths emerge in several weeks to take to the air, mate, and produce eggs to be deposited on a host tree for hatching next year. The favorite host tree in forests of the Lower Susquehanna River Watershed: native Black Cherry.
Here’s a sample of the variety of Neotropical migrants we found in areas impacted by Eastern Tent Caterpillars. All are arboreal insectivores, birds that feed among the foliage of trees and shrubs searching mostly for insects, their larvae, and their eggs.
The Yellow-throated Vireo nests, feeds, and spends the majority of its time feeding among canopy foliage.The Eastern Wood-Pewee is a flycatcher found in mature woodlands. It feeds not only among the limbs and leaves, but is an aerial predator as well.The Northern Parula nests in mature forests along rivers and on mountainsides, particularly where mature trees are draped with thick vines.The Hooded Warbler (Setophaga citrina) is found among thick understory growth on forested slopes.The Ovenbird builds a domed, oven-like nest on the ground and forages in the canopy.The Kentucky Warbler (Geothlypis formosa) nests in woodland undergrowth, often near steep, forested slopes.The Worm-eating Warbler (Helmitheros vermivorum) nests among woody understory growth on forested hillsides.The Scarlet Tanager is often difficult to observe because of its affinity for the canopy of mature forest trees.
In the locations where these photographs were taken, ground-feeding birds, including those species that would normally be common in these habitats, were absent. There were no Gray Catbirds, Carolina Wrens, American Robins or other thrushes seen or heard. One might infer that the arboreal insectivorous birds chose to establish nesting territories where they did largely due to the presence of an abundance of tent caterpillars as a potential food source for their young. That could very well be true—but consider timing.
Already Gone- By the time Neotropical migrants arrive in our area, the larval stages of the Eastern Tent Caterpillar’s life cycle are already coming to an end. The nests that these native insects constructed to capture the energy of the springtime sun have allowed the larvae to exit and browse foliage when conditions were suitable, then return for shelter when they were not. While inside, the larvae could move among the chambers of their structure to find locations with a temperature that best suited their needs. Therein the solar heating and communal warmth sped up digestion and growth.Eastern Tent Caterpillar larvae are now in their bristly final-instar stage and the majority have already moved to the ground to each seek a place to pupate and metamorphose into an adult moth. Arboreal Neotropical birds have scarcely had a chance to feed upon them, and ground-feeding species seem to lack any temptation. As for the adult moths, they fly only at night and live for just one day, offering little in the way of food for aerial, arboreal, or ground-feeding birds.Having left arboreal environs, Eastern Tent Caterpillar larvae are now food for ground-feeding birds like our resident Wild Turkeys. They need only get past the bristly hairs on the caterpillar’s back and the foul taste that may result from its limited diet of cyanogenic Black Cherry leaves.The arboreal Yellow-billed Cuckoo (seen here) and its close relative the Black-billed Cuckoo (Coccyzus erythropthalmus) are the two species of birds in our area known to regularly feed on bristly tent caterpillars. But having just arrived from the tropics to nest, they’ll need to rely on other insects and their larvae as sources of food for their young.Final-instar Eastern Tent Caterpillars often defoliate Black Cherry trees before moving to the ground to pupate. Their timing allows them to feed on the fresh foliage while it is still young and tender, and to largely avoid becoming food for the waves of Neotropical birds that arrive in the lower Susquehanna basin in May.
So why do we find this admirable variety of Neotropical bird species nesting in locations with tent caterpillars? Perhaps it’s a matter of suitable topography, an appropriate variety of native trees and shrubs, and an attractive opening in the forest.
An American Redstart singing in a Black Cherry. Unlike others in the vicinity, this tree nestled among several very large Eastern White Pines showed no signs of tent caterpillar activity. It may be that for one reason or another, no adult female moth deposited her eggs on this particular tree. During our visits, Black Cherry was but one of the diverse variety of native trees and shrubs found growing on the sloping topography that created attractive habitat for the nesting birds we found. We happened to notice that a majority, but not all, of those Black Cherry trees were impacted by Eastern Tent Caterpillars.The end of the Eastern Tent Caterpillar’s larval surge may spell the end of their nests for the year, but it’s not the end for the Black Cherry and other host trees in the Prunus (cherry) and Malus (apple) genera. Because it’s still early in the season, they have plenty of time to re-leaf and many will still flower and produce fruit. Those flowers and foliage will attract numerous other insects (including pollinators) that benefit breeding birds.The Blue-winged Warbler inhabits shrubby breaks in the forest such as this utility right-of-way where Black Cherry trees have sprouted after their seeds arrived in waste deposited by fruit-eating (frugivorous) birds. Already attractive to a variety of insectivores, these openings soon lure egg-laying Eastern Tent Caterpillar moths to the cherry trees growing therein. Even in dense forest, a small clearing created by a cluster of dead trees makes good bird habitat and will sooner or later be visited by fruit-eating species that will inadvertently sow seeds of Black Cherry, starting yet another stand of host trees for Eastern Tent Caterpillars. It’s the gap in the forest that often attracts the birds, some of which plant the host trees, which sometimes entice Eastern Tent Caterpillar moths to lay their eggs.Adapt and Reuse- A Red-eyed Vireo visits an Eastern Tent Caterpillar nest……and ignores the few remaining occupants that could easily be seized to instead collect silk to reinforce its own nest.
Here in the Lower Susquehanna River Watershed, the presence of Eastern Tent Caterpillar nests can often be an indicator of a woodland opening, natural or man-made, that is being reforested by Black Cherry and other plants which improve the botanical richness of the site. For numerous migratory Neotropical species seeking favorable places to nest and raise young, these regenerative areas and the forests surrounding them can be ideal habitat. For us, they can be great places to see and hear colorful birds.
Our Lucky Break- This Scarlet Tanager descended from the treetops to feed on spiders in a small forest clearing.
Following a frosty night, sunny skies and a south breeze brought lots of action to the headquarters garden this morning. Take a look…
Mason Bees are quickly depositing their eggs and a mixture of pollen and nectar called a “pollen loaf” within holes we drilled into blocks of wood in our bee houses. Each egg is laid in its own chamber within which the larva will hatch, feed on “pollen loaf”, and mature. The individual cells, including the outermost one in the hole, are sealed with partitions made of mud. It’s just like a mason using mortar. Early next spring, the new generation of adults will emerge to begin the process once again.This morning’s south wind helped propel some northbound raptors. This Black Vulture was the first we’ve seen from the headquarters garden since last fall. While Turkey Vultures remain common and roost nearby, Black Vulture are noticeably less numerous since being impacted by avian flu one year ago.This Cooper’s Hawk is one of pair nesting somewhere nearby. It was quickly gaining altitude on a thermal……to intercept a transient Cooper’s Hawk (upper right) which it promptly escorted away to the north.Back from their winter holiday in the tropics, migrating Broad-winged Hawks are returning to breed in the forests of the north. Watch for them either singly or in small groups as they “kettle” in thermal updrafts above south-facing slopes and sun-drenched paved surfaces.Many birds including this American Robin have been frequenting our water features. Remember to keep your fixture clean and change the water at least daily. Watch the temperature too. A late season freeze can leave you with a shattered bird bath.
It was dubbed the “Great Solar Eclipse”, the Great North American Eclipse”, and several other lofty names, but in the lower Susquehanna valley, where about 92% of totality was anticipated, the big show was nearly eclipsed by cloud cover. With last week’s rains raising the waters of the river and inundating the moonscape of the Pothole Rocks at Conewago Falls, we didn’t have the option of repeating our eclipse observations of August, 2017, by going there to view this year’s event, so we settled for the next best thing—setting up in the susquehannawildlife.net headquarters garden. So here it is, yesterday’s eclipse…
Here’s one of our first views through a break in the clouds as photographed using a number 12 welder’s glass to shield the camera.A shot through the welder’s glass with minimal cloud cover reveals a sunspot (AR3628) visible at between ten and eleven o’clock on the solar surface.Clouds aren’t necessarily a bad thing during a solar eclipse. Putting the welding filter aside, we were able to photograph the sun directly, without risk of damage to the camera. Again, sunspot AR3628 can be seen just off the limb of the moon at between ten and eleven o’clock.It’s 3:21 P.M. E.D.T., and it’s about as good as it’s going to get. Fortunately for us, the clouds are maximizing the effect.The sky darkened dramatically as the moon obscured more than 90% of the sun’s disk. Looking toward the northwest, where observers in locations including Erie, Pennsylvania, were experiencing a total solar eclipse, the sky appeared almost night-like.Here in the lower Susquehanna region, the clouds made our partial solar eclipse an eerie one.Our home-brew solar-powered radio shut down.Our male Mourning Dove perched above its nests site and began a premature evening chorus of sorrowful coos.The flock of Fish Crows that has been lingering in the area for several weeks was seen making their way to a small grove of nearby evergreens where they often spend the night.Since early winter, Turkey Vultures have been roosting at a site about a half mile from our headquarters. Each evening, they can be seen leisurely riding the late afternoon thermals as they glide in to pass the night at their favored resting spot. During the height of the eclipse, as clouds co-conspired to quickly darken the sky and diminish the thermal updrafts, our local vultures were making a hurried scramble, flapping madly to get back to their roost.Within fifteen minutes, the cloud cover thinned and the moon started to slide away. Rays of sunshine quickly renewed the pace of an early spring afternoon. Soon, the bees were buzzing around, the crows were out looking for trash, and the vultures were piloting the skies in search of deadbeats.The Great Eclipse of 2024 left us with a sunny smile.
Homo sapiens owes much of its success as a species to an acquired knowledge of how to make, control, and utilize fire. Using fire to convert the energy stored in combustible materials into light and heat has enabled humankind to expand its range throughout the globe. Indeed, humans in their furless incomplete mammalian state may have never been able to expand their populations outside of tropical latitudes without mastery of fire. It is fire that has enabled man to exploit more of the earth’s resources than any other species. From cooking otherwise unpalatable foods to powering the modern industrial society, fire has set man apart from the rest of the natural world.
In our modern civilizations, we generally look at the unplanned outbreak of fire as a catastrophe requiring our immediate intercession. A building fire, for example, is extinguished as quickly as possible to save lives and property. And fires detected in fields, brush, and woodlands are promptly controlled to prevent their exponential growth. But has fire gone to our heads? Do we have an anthropocentric view of fire? Aren’t there naturally occurring fires that are essential to the health of some of the world’s ecosystems? And to our own safety? Indeed there are. And many species and the ecosystems they inhabit rely on the periodic occurrence of fire to maintain their health and vigor.
For the war effort- The campaign to reduce the frequency of forest fires got its start during World War II with distribution of this poster in 1942. The goal was to protect the nation’s timber resources from accidental or malicious loss due to fire caused by man-made ignition sources. The release of the Walt Disney film “Bambi” during the same year and the adoption of the Smokey the Bear mascot in 1944 softened the message’s delivery, but the public relations outreach continued to be a key element of a no-fire policy to save trees for lumber. Protection and management of healthy forest ecosystems in their entirety has only recently become a priority. (National Archives image)
Man has been availed of the direct benefits of fire for possibly 40,000 years or more. Here in the Lower Susquehanna River Watershed, the earliest humans arrived as early as 12,000 years ago—already possessing skills for using fire. Native plants and animals on the other hand, have been part of the ever-changing mix of ecosystems found here for a much longer period of time—millions to tens of millions of years. Many terrestrial native species are adapted to the periodic occurrence of fire. Some, in fact, require it. Most upland ecosystems need an occasional dose of fire, usually ignited by lightning (though volcanism and incoming cosmic projectiles are rare possibilities), to regenerate vegetation, release nutrients, and maintain certain non-climax habitat types.
But much of our region has been deprived of natural-type fires since the time of the clearcutting of the virgin forests during the eighteenth and nineteenth centuries. This absence of a natural fire cycle has contributed to degradation and/or elimination of many forest and non-forest habitats. Without fire, a dangerous stockpile of combustible debris has been collecting, season after season, in some areas for a hundred years or more. Lacking periodic fires or sufficient moisture to sustain prompt decomposition of dead material, wildlands can accumulate enough leaf litter, thatch, dry brush, tinder, and fallen wood to fuel monumentally large forest fires—fires similar to those recently engulfing some areas of the American west. So elimination of natural fire isn’t just a problem for native plants and animals, its a potential problem for humans as well.
Indiangrass (seen here), Switchgrass, Big Bluestem, and Little Bluestem are native species requiring periodic forms of disturbance to eliminate competition by woody plants. These warm-season grasses develop roots that penetrate deep into the soil, sometimes to depths of six feet or more, allowing them to survive severe drought and flash fire events. In the tall grass prairies, these extensive root systems allow these grasses to return following heavy grazing by roaming herds of American Bison (Bison bison). Without these habitat disturbances, warm season grasslands succumb to succession in about seven years. With their periodic occurrence, the plants thrive and provide excellent wildlife habitat, erosion control, and grazing forage.
To address the habitat ailments caused by a lack of natural fires, federal, state, and local conservation agencies are adopting the practice of “prescribed fire” as a treatment to restore ecosystem health. A prescribed fire is a controlled burn specifically planned to correct one or more vegetative management problems on a given parcel of land. In the Lower Susquehanna River Watershed, prescribed fire is used to…
Eliminate dangerous accumulations of combustible fuels in woodlands.
Reduce accumulations of dead plant material that may harbor disease.
Provide top kill to promote oak regeneration.
Regenerate other targeted species of trees, wildflowers, grasses, and vegetation.
Kill non-native plants and promote growth of native plants.
Prevent succession.
Remove woody growth and thatch from grasslands.
Promote fire tolerant species of plants and animals.
Improve habitat for rare species (Regal Fritillary, etc.)
Recycle nutrients and minerals contained in dead plant material.
Let’s look at some examples of prescribed fire being implemented right here in our own neighborhood…
Prescribed fires are typically planned for the dormant season extending from late fall into early spring with burns best conducted on days when the relative humidity is low.Prescribed fire is used regularly at Fort Indiantown Gap Military Reservation in Lebanon County, Pennsylvania, to keep accumulations of woody and herbaceous fuels from accumulating on and around the training range areas where live ordinance and other sources of ignition could otherwise spark large, hard-to-control wildfires.Prescribed fires replace the periodic natural burns that would normally reduce the fuel load in forested areas. Where these fuels are allowed to accumulate, south-facing slopes are particularly susceptible to extreme fires due to their exposure to the drying effects of intense sunlight for much of the year. The majority of small oaks subjected to treatment by the prescribed fire shown here will have the chance to regenerate without immediate competition from other species including invasive plants. The larger trees are mostly unaffected by the quick exposure to the flames. Note too that these fires don’t completely burn everything on the forest floor, they burn that which is most combustible. There are still plenty of fallen logs for salamanders, skinks, and other animals to live beneath and within.
A prescribed fire in late winter prevents this grassland consisting of Big Bluestem and native wildflowers from being overtaken by woody growth and invasive species. Fires such as this that are intended to interrupt the process of succession are repeated at least every three to five years.In its wildlife food plots, prescribed fire is used by the Pennsylvania Game Commission to prevent succession and control invasive species such as Multiflora Rose, instead promoting the growth of native plants.An example of a woodlot understory choked with combustible fuels and dense tangles of invasive Multiflora Rose. A forester has the option of prescribing a dose of dormant-season fire for a site like this to reduce the fuel load, top kill non-native vegetation, and regenerate native plants.A dose of prescribed fire was administered on this grassland to kill the woody growth of small trees beginning to overtake the habitat by succession.The Pennsylvania Game Commission employs prescribed fire at Middle Creek Wildlife Management Area and on many of their other holdings to maintain grasslands.Prescribed fire is used to eliminate invasive species including Multiflora Rose from grasslands at Middle Creek W.M.A. Annual burns on the property are conducted in a mosaic pattern so that each individual area of the grassland is exposed to the effects of fire only once every two to five years. Without fire or some type of mechanical or chemical intervention, succession by woody trees and shrubs would take hold after about seven years.Prescribed fire is planned for a fraction of total grassland acreage at Middle Creek W.M.A. each year. Another section of the mosaic is targeted in the following year and yet another in the year that follows that. Because burns are conducted in the spring, grassland cover is available for wildlife throughout the winter. And because each year’s fire burns only a portion of the total grassland acreage, wildlife still has plenty of standing grass in which to take shelter during and after the prescribed fire.Prescribed fire at Middle Creek W.M.A. provides grassland habitat for dozens of species of birds and mammals including the not-so-common Grasshopper Sparrow……and stocked Ring-necked Pheasants that do nest and raise young there.On a few sites in the Lower Susquehanna River Watershed , prescribed fire is being used to establish and maintain savanna-like grasslands. This one, located on a dry, south-facing slope near numerous man-made sources of ignition, can easily be dosed with periodic prescribed burns to both prevent succession and reduce fuel accumulations that may lead to a devastating extreme fire.One year following a prescribed burn, this is the autumn appearance of a savanna-like habitat with fire-tolerant Pitch Pine (Pinus rigida), Bear Oak, warm-season grasses, and a variety of nectar-producing wildflowers for pollinators. These ecosystems are magnets for wildlife and may prove to be a manageable fit on sun-drenched sites adjacent to man-made land disturbances and their sources of ignition.Savanna-like grasslands with oaks and other scattered large trees, some of them dead, make attractive nesting habitat for the uncommon Red-headed Woodpecker.Prescribed fire can benefit hungry Wild Turkeys by maintaining savanna-like grasslands for an abundance of grasshoppers and other insects in summer and improving the success of mast-producing oaks for winter.In the Lower Susquehanna River Watershed, the caterpillar of the rare Eastern Buck Moth feeds on the foliage of the Bear Oak, also known as the Scrub Oak, a shrubby species that relies upon periodic fire to eliminate competition from larger trees in its early successional habitat.Leaves of the Bear Oak in fall. The Bear Oak regenerates readily from top kill caused by fire.Reed Canary Grass (Phalaris arundinacea) is a native cool-season grass with a colorful inflorescence in spring. But given the right situation, it can aggressively overtake other species to create a pure stand lacking biodiversity. It is one of the few native species which is sometimes labelled “invasive”.Prescribed fire can be used to reduce an overabundance of Reed Canary Grass and its thatch in wetlands. Periodic burning can help restore species diversity in these habitats for plants and animals including rare species such as the endangered Bog Turtle (Glyptemys muhlenbergii).On the range areas at Fort Indiantown Gap in Lebanon County, Pennsylvania, disturbances by armored vehicles mimic the effects of large mammals such as the American Bison which periodically trampled grasses to prevent succession and the establishment of woody plants on its prairie habitat. To supplement the activity of the heavy vehicles and to provide suitable habitat for the very rare Regal Fritillary (Speyeria idalia) butterflies found there, prescribed fire is periodically employed to maintain the grasslands on the range. These burns are planned to encourage the growth of “Fort Indiantown Gap Little Bluestem” grass as well as the violets used as host plants by the Regal Fritillary caterpillars. These fires also promote growth of a variety of native summer-blooming wildflowers to provide nectar for the adults butterflies.A last record of a wild American Bison killed in Pennsylvania was an animal taken in the Susquehanna watershed in Union County in 1801. The species is thereafter considered extirpated from the state. Since that time, natural disturbances needed to regenerate warm-season grasses have been limited primarily to fires and riverine ice scour. The waning occurrence of both has reduced the range of these grasses and their prairie-like ecosystems in the commonwealth. (Exhibit: State Museum of Pennsylvania, Harrisburg)A male Regal Fritillary on the range at Fort Indiantown Gap, where armored vehicles and prescribed fire provide suitable prairie-like habitat for this vulnerable species.Prescribed fires return the nutrients and minerals contained in dead plant material to the soil. Following these controlled burns, insects like this Honey Bee can often be seen collecting minerals from the ashes.A Greenbottle Fly gathering minerals from the ash following a prescribed burn.
In Pennsylvania, state law provides landowners and crews conducting prescribed fire burns with reduced legal liability when the latter meet certain educational, planning, and operational requirements. This law may help encourage more widespread application of prescribed fire in the state’s forests and other ecosystems where essential periodic fire has been absent for so very long. Currently in the Lower Susquehanna River Watershed, prescribed fire is most frequently being employed by state agencies on state lands—in particular, the Department of Conservation and Natural Resources on State Forests and the Pennsylvania Game Commission on State Game Lands. Prescribed fire is also part of the vegetation management plan at Fort Indiantown Gap Military Reservation and on the land holdings of the Hershey Trust. Visitors to the nearby Gettysburg National Military Park will also notice prescribed fire being used to maintain the grassland restorations there.
For crews administering prescribed fire burns, late March and early April are a busy time. The relative humidity is often at its lowest level of the year, so the probability of ignition of previous years’ growth is generally at its best. We visited with a crew administering a prescribed fire at Middle Creek Wildlife Management Area last week. Have a look…
Members of a Pennsylvania Game Commission burn crew provide visitors to Middle Creek Wildlife Management Area with an overview of prescribed fire and the equipment and techniques they use to conduct a burn.Pennsylvania Game Commission Southeast Region Forester Andy Weaver will fulfill the role of Burn Boss for administering this day’s dose of fire. His responsibilities include assessing the weather before the burn and calculating a probability of ignition.The Burn Boss briefs personnel with information on site layout, water supply location(s), places of refuge, emergency procedures, the event’s goals and plan of action, crew assignments, and the results of the weather check: wind from the northwest at 5 miles per hour, temperature 48 degrees, and the relative humidity 63%. Today’s patient is a parcel of warm-season grasses receiving a dose of fire to eliminate invasive non-native plants, woody growth, and thatch. The probability of ignition is 20%, but improving by the minute.To begin the burn, a test fire is started in the downwind corner of the parcel, which also happens to be the bottom of the slope. Fuel ignition is good. The burn can proceed.Crews proceed uphill from the location of the test fire while igniting combustibles along both flanks of the area being treated.A drip torch is used to ignite the dried stems and leaves of warm-season grasses and wildflowers. Each member of the burn crew wears Nomex fire-resistant clothing and carries safety equipment including a two-way radio, a hydration pack, and a cocoon-like emergency fire shelter.An all-terrain vehicle equipped with various tools, a fire pump, hose, and a small water tank accompanies the crew on each flank of the fire.A mowed strip of cool-season grasses along the perimeter of the burn area is already green and functions as an ideal fire break. While the drip torch is perfect for lighting combustibles along the fire’s perimeter, the paintball gun-looking device is an effective tool used to lob incendiaries into the center areas of the burn zone for ignition.With green cool-season grasses already growing on the trails surrounding the burn zone, very little water was used to contain this prescribed fire. Where such convenient fire breaks don’t already exist, crews carry tools including chain saws, shovels, and leaf blowers to create their own. They also carry flame swatters, backpack water pumps, shovels, and other tools to extinguish fires if necessary. None of these items were needed to control this particular fire.This fast-burning fire provides enough heat to damage the cambium layer of the woody tree and shrub saplings in this parcel being maintained as a grassland/wildflower plot, thus the process of succession is forestalled. Burns conducted during previous years on this and adjacent fields have also controlled aggressive growth of invasive Multiflora Rose and Olives (Elaeagnus species).Crews proceed up the slope while maintaining the perimeter by igniting dry plant material along the flanks of the burn zone.Ignition complete, the crews monitor the fire.The Burn Boss surveys the final stages of a safe and successful prescribed fire. The fire has left behind a mosaic of burned and unburned areas, just as a naturally occurring event may have done. Wildlife dodging the flames may be taking refuge in the standing grasses, so there is no remedial attempt to go back and ignite these areas. They’ll be burned during prescribed fires in coming years.By June, this grassland will again be lush and green with warm-season grasses and blooming wildflowers like this Common Milkweed being visited by a Great Spangled Fritillary.And later in the summer, Eastern Tiger Swallowtails on Joe-pye Weed.Indiangrass in flower in mid-summer.Bobolinks glow in the late August sun while taking flight from a stand of warm-season grasses maintained using springtime prescribed fire. The small dots on the dark background at the top of the image are multitudes of flying insects, many of them pollinators. The vegetation is predominately Indiangrass, excellent winter cover for birds, mammals, and other wildlife.
Prescribed burns aren’t a cure-all for what ails a troubled forest or other ecosystem, but they can be an effective remedy for deficiencies caused by a lack of periodic episodes of naturally occurring fire. They are an important option for modern foresters, wildlife managers, and other conservationists.
It’s that time of year. Your local county conservation district is taking orders for their annual tree sale and it’s a deal that can’t be beat. Order now for pickup in April.
The prices are a bargain and the selection includes the varieties you need to improve wildlife habitat and water quality on your property. For species descriptions and more details, visit each tree sale web page (click the sale name highlighted in blue). And don’t forget to order packs of evergreens for planting in mixed clumps and groves to provide winter shelter and summertime nesting sites for our local native birds. They’re only $12.00 for a bundle of 10.
It’s the most desirable block in town, not because the houses are any different from others built during the post-war years of the mid-twentieth century, but because the first owners of these domiciles had the good taste and foresight to plant long-lived trees on their lots, the majority of them native species. Pin Oak, Northern Red Oak, Yellow Poplar, Flowering Dogwood (Cornus florida), Eastern Red Cedar, Eastern White Pine, Eastern Hemlock, Norway Spruce, and American Holly dominate the landscape and create excellent habitat for birds and other wildlife. These 75-year-old plantings provide an abundance of shade in summer and thermal stability in winter, making it a “cool” place to live or take a stroll at any time of the year.
Pickup on: Thursday, April 18, 2024 or Friday, April 19, 2024
Cumberland County Conservation District is taking orders for Common Winterberry, the ideal small shrub for wet soil anywhere on your property. To get berries, you’ll need both males and females, so buy a bunch and plant them in a clump or scattered group.To live for a century or more like this towering giant, a Pin Oak needs to grow in well-drained soils with adequate moisture. These sturdy shade providers do well along streams and on low ground receiving clean runoff from hillsides, roofs, streets, and parking areas. As they age, Pin Oaks can fail to thrive and may become vulnerable to disease in locations where rainfall is not adequately infiltrated into the soil. Therefore, in drier areas such as raised ground or slopes, avoid the Pin Oak and select the more durable Northern Red Oak for planting. This year, Pin Oaks are available from the Cumberland and Lancaster County Conservation Districts, while Dauphin, Lancaster, Lebanon, and York Counties are taking orders for Northern Red Oaks.The Cumberland County Conservation District is again offering a “Showy Northeast Native Wildflower and Grass Mix” for seeding your own pollinator meadow or garden. It consists of more than twenty species including this perennial favorite, Purple Coneflower.
Pickup on: Thursday, April 18, 2024 or Friday, April 19, 2024
The Eastern Redbud is small tree native to our forest edges, particularly in areas of the Piedmont Province with Triassic geology (Furnace Hills, Conewago Hills, Gettysburg/Hammer Creek Formations, etc.) Also known as the Judas Tree, the redbud’s brilliant flowers are followed by heart-shaped leaves. As seen here, it is suitable for planting near houses and other buildings. Eastern Redbud seedlings are being offered through tree sales in Dauphin, Cumberland, and Lancaster Counties.
The Yellow Poplar, often called Tuliptree or Tulip Poplar for its showy flowers, is a sturdy, fast-growing deciduous tree native to forests throughout the Lower Susquehanna River Watershed. Its pole-straight growth habit in shady woodlands becomes more spreading and picturesque when the plant is grown as a specimen or shade tree in an urban or suburban setting. The Yellow Poplar can live for hundreds of years and is a host plant for the Eastern Tiger Swallowtail butterfly. It is available this year from the Lancaster County Conservation District.The American Sweetgum, also known as Sweet Gum, is a large, long-lived tree adorned with a mix of vibrant colors in autumn.Ever wonder where all the American Goldfinches and particularly the Pine Siskins go after passing through our region in fall? Well, many are headed to the lowland forests of the Atlantic Coastal Plain where they feed on an abundance of seeds contained in spiky American Sweetgum fruits. In the Piedmont and Ridge and Valley Provinces of the Lower Susquehanna River Watershed, American Sweetgum transplants can provide enough sustenance to sometimes lure our friendly finches into lingering through the winter.The American Sweetgum is a versatile tree. It can be planted on upland sites as well as in wet ground along streams, lakes, and rivers. In the beaver pond seen here it is the dominate tree species. This year, you can buy the American Sweetgum from the Lancaster County Conservation District.“Red-twig Dogwood” is a group of similar native shrubs that, in our region, includes Silky Dogwood and the more northerly Red-Osier Dogwood (Cornus sericea). Both have clusters of white flowers in spring and showy red twigs in winter. They are an excellent choice for wet soils. Landscapers often ruin these plants by shearing them off horizontally a foot or two from the ground each year. To produce flowers and fruit, and to preserve winter attractiveness, trim them during dormancy by removing three-year-old and older canes at ground level, letting younger growth untouched.“Red-twig Dogwoods” make ideal mass plantings for streamside buffers and remain showy through winter, even on a gloomy day. They not only mitigate nutrient and sediment pollution, they provide excellent food and cover for birds and other wildlife. Both Silky and Red-osier Dogwoods are available for sale through the Lancaster County Conservation District as part of their special multi-species offers, the former is included in its “Beauty Pack” and the latter in its “Wildlife Pack”. The similar Gray Dogwood (Cornus racemosa) is being offered for sale by the York County Conservation District.
The unique maroon flowers of the Common Pawpaw produce banana-like fruits in summer. These small native trees grow best in damp, well-drained soils on slopes along waterways, where they often form clonal understory patches. To get fruit, plant a small grove to increase the probability of pollination. The Common Pawpaw is a host plant for the Zebra Swallowtail butterfly. It is available through both the Lebanon and Lancaster County sales.The Eastern Red Cedar provides excellent food, cover, and nesting sites for numerous songbirds. Planted in clumps of dozens or groves of hundreds of trees, they can provide winter shelter for larger animals including deer and owls. The Eastern Red Cedar is being offered for purchase through both the Lebanon and Lancaster County Conservation Districts.Care to try your hand at raising some chestnuts? Lebanon County Conservation District has hybrid American Chestnut seedlings for sale.Lebanon County Conservation District is offering Common Winterberry and Eastern White Pine during their 2024 Tree and Plant Sale. Plant them both for striking color during the colder months. Eastern White Pine is also available from the Cumberland, Dauphin, Lancaster, and York County sales.
In addition to a selection of trees and shrubs, the Perry County Conservation District is again selling wildflower seed mixes for starting your own pollinator meadow or garden. For 2024, they have both a “Northeast Perennials and Annuals Mix” and a “Butterfly and Hummingbird Seed Mix” available. Give them a try so you can give up the mower!
Again this year, Perry County is offering bluebird nest boxes for sale. The price?—just $12.00.
Wait, what?,…twelve bucks,…that’s cheaper than renting!
The Buttonbush, a shrub of wet soils, produces a cosmic-looking flower. It grows well in wetlands, along streams, and in rain gardens. Buttonbush seedlings are for sale from both the York and Lancaster County Conservation Districts.
To get your deciduous trees like gums, maples, oaks, birches, and poplars off to a safe start, conservation district tree sales in Cumberland, Dauphin, Lancaster, and Perry Counties are offering protective tree shelters. Consider purchasing these plastic tubes and supporting stakes for each of your hardwoods, especially if you have hungry deer in your neighborhood.
Tree shelters protect newly transplanted seedlings from browsing deer, klutzy hikers, visually impaired mower operators, and other hazards.
There you have it. Be sure to check out each tree sale’s web page to find the selections you like, then get your order placed. The deadlines will be here before you know it and you wouldn’t want to miss values like these!
Just as bare ground along a plowed road attracts birds in an otherwise snow-covered landscape, a receding river or large stream can provide the same benefit to hungry avians looking for food following a winter storm.
Here is a small sample of some of the species seen during a brief stop along the Susquehanna earlier this week.
Along vegetated edges of the Susquehanna and its tributaries, the Song Sparrow is ubiquitous in its search for small seeds and other foods. As the river recedes from the effects of this month’s rains, the shoreline is left bare of more recently deposited snow cover. Song Sparrows and other birds are attracted to streamside corridors of frost-free ground to find sufficient consumables for supplying enough energy to survive the long cold nights of winter.Thousands of American Robins have been widespread throughout the lower Susquehanna valley during the past week. Due to the mild weather during this late fall and early winter, some may still be in the process of working their way south. Currently, many robins are concentrated along the river shoreline where receding water has exposed unfrozen soils to provide these birds with opportunities for finding earthworms (Lumbricidae) and other annelids.This Golden-crowned Kinglet was observed searching the trees and shrubs along the Susquehanna shoreline for tiny insects and spiders. Temperatures above the bare ground along the receding river can be a few degrees higher than in surrounding snow-covered areas, thus improving the chances of finding active prey among the trunks and limbs of the riparian forest.Not far from the kinglet, a Brown Creeper is seen searching the bark of a Silver Maple (Acer saccharinum) for wintering insects, as well as their eggs and larvae. Spiders in all their life stages are a favorite too.American Pipits not only inhabit farm fields during the winter months, they are quite fond of bare ground along the Susquehanna. Seen quite easily along a strip of pebbly shoreline exposed by receding water, these birds will often escape notice when spending time on mid-river gravel and sand bars during periods of low flow.An American Pipit on a bitterly cold afternoon along the Susquehanna.
What was the attraction that prompted dozens of birders to hike more than a mile to a secluded field edge along the Northwest Lancaster County River Trail on this last full day of autumn? It must be something good.
Birders photographing a rarity in the vicinity of the Shock’s Mill Railroad Bridge along the Susquehanna in Conoy Township, Lancaster County, earlier today.
Indeed it was. A Western Flycatcher (Empidonax difficilis), first discovered late last week, has weathered the coastal storm that in recent days pummeled the Lower Susquehanna River Watershed with several inches of rain and blustery winds. Western Flycatchers nest in the Rocky Mountain and Pacific Coast regions of North America. They spend their winters in Mexico. There are several records of these tiny passerines in our area during December. The first, a bird found in an area known as Tanglewood during the Southern Lancaster County Christmas Bird Count (CBC) on December 16, 1990, was well documented—photographs were taken and its call was tape recorded. It constituted the first record of a member of the Western Flycatcher’s “Pacific-slope” subspecies group ever seen east of the Mississippi River. It was reported through December 26, 1990. The Tanglewood flycatcher and a bird sighted years later on a subsequent “Solanco CBC” were both found inhabiting wooded thickets in the shelter of a ravine created by one of the Susquehanna’s small tributaries.
Early this morning, a vagrant Western Flycatcher finds a sunny spot adjacent to the Northwest Lancaster County River Trail to search the vines, shrubs, and tree limbs for spiders and small insects.The diminutive Western Flycatcher on the lookout for flying insects from an elevated perch in the treetops.Like other Western Flycatchers which have been found during the month of December in Lancaster County, this individual has some topographic protection from cold northwest winds. It spends its time in a thicket along the edge of woodlands on the leeward side of the railroad grade that rises as the approach to the nearby Shock’s Mill Bridge.
How long will this wandering rarity remain along the river trail? For added sustenance, sunny days throughout the coming winter offer ever-increasing chances of stonefly hatches on the adjacent river, particularly in the vicinity of the stone bridge piers. But ultimately, the severity of the weather and the bird’s response to it will determine its destiny.
Only fools mess around with bees, wasps, and hornets as they collect nectar and go about their business while visiting flowering plants. Relentlessly curious predators and other trouble makers quickly learn that patterns of white, yellow, or orange contrasting with black are a warning that the pain and anguish of being zapped with a venomous sting awaits those who throw caution to the wind. Through the process of natural selection, many venomous and poisonous animals have developed conspicuously bright or contrasting color schemes to deter would-be predators and molesters from making such a big mistake.
The brilliant colors of the “Red Eft”, the terrestrial sub-adult stage of the aquatic Eastern Newt (Notophthalmus viridescens), provide protection not as a form of camouflage, but as a warning to potential predators that “I am inedible” due to the presence of tetrodotoxin, a strong neurotoxin. Over the generations, natural selection has better enabled the brightest of the individual “Red Efts” to survive to adulthood and reproduce. Meanwhile, those efts that provided a less obvious visual clue to their toxicity frequently allowed their pursuer to learn of their defense mechanism by the taste-test method. As one might expect, far fewer of these latter individuals survived to breed and pass along their more cryptic color variation.
Visual warnings enhance the effectiveness of the defensive measures possessed by venomous, poisonous, and distasteful creatures. Aggressors learn to associate the presence of these color patterns with the experience of pain and discomfort. Thereafter, they keep their distance to avoid any trouble. In return, the potential victims of this unsolicited aggression escape injury and retain their defenses for use against yet-to-be-enlightened pursuers. Thanks to their threatening appearance, the chances of survival are increased for these would-be victims without the need to risk death or injury while deploying their venomous stingers, poisonous compounds, or other defensive measures.
Armed and Dangerous The yellow-and-black color pattern on this European Paper Wasp signals a potential aggressor that they have come upon a social insect and could be struck with a venomous sting. The warning colors alone may be all the defenses necessary for this wasp to survive an otherwise fatal encounter.
One shouldn’t be surprised to learn that over time, as these aforementioned venomous, poisonous, and foul-tasting critters developed their patterns of warning colors, there were numerous harmless animals living within close association with these species that, through the process of natural selection, acquired nearly identical color patterns for their own protection from predators. This form of defensive impersonation is known as Batesian mimicry.
Let’s take a look at some examples of Batesian mimicry right here in the Lower Susquehanna River Watershed.
Suppose for a moment that you were a fly. As you might expect, you would have plenty to fear while you spend your day visiting flowers in search of energy-rich nectar—hundreds of hungry birds and other animals want to eat you.
You might not hurt a fly, but plenty of other creatures will. This Greenbottle Fly relies upon speed and maneuverability to quickly flee predators.Like the Greenbottle Fly, the Common Flesh Fly (Sarcophaga species) needs to be constantly vigilant and survives by being quick to the wing.
If you were a fly and you were headed out and about to call upon numerous nectar-producing flowers so you could round up some sweet treats, wouldn’t you feel a whole lot safer if you looked like those venomous bees, wasps, and hornets in your neighborhood? Wouldn’t it be a whole lot more fun to look scary—so scary that would-be aggressors fear that you might sting them if they gave you any trouble?
Suppose Mother Nature and Father Time dressed you up to look like a bee or a wasp instead of a helpless fly? Then maybe you could go out and collect sweets without always worrying about the bullies and the brutes, just like these flies of the lower Susquehanna do…
FLOWER FLIES/HOVER FLIES
The Common Drone Fly (Eristalis tenax) is an unarmed Honey Bee mimic. This one is gathering nectar on goldenrod flowers.The Transverse Flower Fly (Eristalis transversa) is another bee mimic. Members of the genus Eristalis scavenge carcasses in aquatic habitats. Their larvae are known as rat-tailed maggots, a name that references their long siphons used for breathing surface air while submerged in ponds, streams, and wetlands.Flower flies of the genus Spilomyia are convincing mimics of temperamental yellowjacket wasps.The Yellowjacket Hover Fly (Milesia virginiensis) is usually heard long before it is seen. It will often approach people and persist with a loud buzzing, sounding more like a bee than a bee does. Scary, isn’t it?The Maize Calligrapher (Toxomerus politus) is a hover fly mimic of wasps. Seen here on Indiangrass, it is believed to associate primarily with Corn (Zea mays).The Narrow-headed Marsh Fly (Helophilus fasciatus) is a wasp mimic. Like other mimics of hymenopterans, they are important pollinators of flowering plants.This hover fly of the genus Syrphus is another wasp mimic.
TACHINID FLIES
The Feather-legged Fly (Trichopoda species) is a wasp mimic. Its larvae are parasitoids of stink bugs and leaf-footed bugs.
BEE FLIES
Bee flies of the genus Exoprosopa convincingly resemble bumble bees.The larvae of Exoprosopa bee flies are believed to be parasitic on the larvae of the parasites of bee and wasp larvae that mature in the soil. Confused yet?
So let’s review. If you’re a poor defenseless fly and you want to get your fair share of sweets without being gobbled up by the beasts, then you’ve got to masquerade like a strongly armed member of a social colony—like a bee, wasp, or hornet. Now look scary and go get your treats. HAPPY HALLOWEEN!
With nearly all of the Neotropical migrants including Broad-winged Hawks gone for the year, observers and counters at eastern hawk watches are busy tallying numbers of the more hardy species of diurnal raptors and other birds. The majority of species now coming through will spend the winter months in temperate and sub-tropical areas of the southern United States and Mexico.
Here is a quick look at the raptors seen this week at two regional counting stations: Kiptopeke Hawk Watch near Cape Charles, Virginia, and Second Mountain Hawk Watch at Fort Indiantown Gap, Pennsylvania.
The hawk-watching platform at Kiptopeke State Park is located along Chesapeake Bay near the southern tip of Delmarva Peninsula. In autumn, thousands of raptors and other birds migrate through the Atlantic Coastal Plain Province. Those that follow the shorelines south frequently concentrate in spectacular numbers before crossing the mouths of the bays they encounter. This phenomenon makes both Cape May, New Jersey, on Delaware Bay and Kiptopeke, Virginia, on Chesapeake Bay exceptional places to experience fall flights of migrating birds.A Sharp-shinned Hawk is counted as it swoops by the owl decoy at Second Mountain Hawk Watch at Fort Indiantown Gap Military Reservation. Migrating raptors save energy by riding updrafts of air created by winds blowing against the slopes of the mountainsides in the Ridge and Valley Province.A Sharp-shinned Hawk passes the lookout at Second Mountain Hawk Watch. “Sharp-shins” are currently the most numerous migrants both on the coast and at inland counting stations.A Sharp-shinned Hawk nearly passes observers unnoticed as it skims the treetops.A Sharp-shinned Hawk eyes up an owl decoy. Under cover of darkness, nocturnal owls could rather easily prey upon young and small adult hawks and falcons, both on the nest or at roost. Accordingly, many diurnal raptors instinctively harass owls to drive them from their presence. An owl decoy at the lookout helps attract migrating birds for a closer look.An adult Cooper’s Hawk flaps its way past a counting station. Like the similar Sharp-shinned Hawk, the larger Cooper’s Hawk is a member of the genus Accipiter. As a proportion of the annual fall Accipiter flight, the Cooper’s Hawk is more numerous at coastal hawk watches than at inland sites.The majority of Osprey migrate along the coast, but a few are still being seen at inland hawk watches.Bald Eagles are commonly seen at both coastal and inland lookouts. Their movements continue well into late fall.A Northern Harrier illuminated by a setting sun. Northern Harriers are often still flying when many other species have gone to roost for the day.An adult male Northern Harrier, the “gray ghost”, flying in misty weather, at a time when few other birds were in the air. The American Kestrel, like our other falcons, is seen in greatest concentrations at coastal counting stations. It is our most numerous falcon.The Merlin provides only a brief observation opportunity as it passes the lookout. These falcons are dark, speedy, and easily missed as they fly by.While moving south, Merlins often accompany flights of migrating Tree Swallows, a potential food source.A Merlin consumes a dragonfly. Eating is no reason to stop moving.The “Tundra Peregrine” is an arctic-breeding Peregrine Falcon that travels a distance of over 6,000 miles to southern South America for winter. It is strictly a migratory species in our region with numbers peaking during the first two weeks of October each year. These strong fliers have little need for the updrafts from mountain ridges, inland birds often observed flying in a north to south direction. The majority of “Tundra Peregrines” are observed following coastlines, with some migrating offshore to make landfall at points as far south as Florida and the Caribbean islands before continuing across water again to reach the northern shores of Central and South America. This “Tundra Peregrine” is a juvenile bird on its first southbound trip.
During coming days, fewer and fewer of these birds will be counted at our local hawk watches. Soon, the larger raptors—Red-tailed Hawks, Red-shouldered Hawks, and Golden Eagles—will be thrilling observers. Cooler weather will bring several flights of these spectacular species. Why not plan a visit to a lookout near you? Click on the “Hawkwatcher’s Helper: Identifying Bald Eagles and other Diurnal Raptors” tab at the top of this page for site information and a photo guide to identification. See you at the hawk watch!
It’s not all hawks at the hawk watch. Even the coastal sites are now seeing fun birds like the playful Common Raven on a regular basis.Coastal locations are renowned places to see migrating songbirds in places outside of their typical habitat. Here a flock of Eastern Meadowlarks has set down in the top of a Loblolly Pine (Pinus taeda) in downtown Cape Charles, Virginia, not far from Kiptopeke Hawk Watch.
What’s all this buzz about bees? And what’s a hymanopteran? Well, let’s see.
Hymanoptera—our bees, wasps, hornets and ants—are generally considered to be our most evolved insects. Some form complex social colonies. Others lead solitary lives. Many are essential pollinators of flowering plants, including cultivars that provide food for people around the world. There are those with stingers for disabling prey and defending themselves and their nests. And then there are those without stingers. The predatory species are frequently regarded to be the most significant biological controls of the insects that might otherwise become destructive pests. The vast majority of the Hymanoptera show no aggression toward humans, a demeanor that is seldom reciprocated.
Late summer and early autumn is a critical time for the Hymanoptera. Most species are at their peak of abundance during this time of year, but many of the adult insects face certain death with the coming of freezing weather. Those that will perish are busy, either individually or as members of a colony, creating shelter and gathering food to nourish the larvae that will repopulate the environs with a new generation of adults next year. Without abundant sources of protein and carbohydrates, these efforts can quickly fail. Protein is stored for use by the larval insects upon hatching from their eggs. Because the eggs are typically deposited in a cell directly upon the cache of protein, the larvae can begin feeding and growing immediately. To provide energy for collecting protein and nesting materials, and in some cases excavating nest chambers, Hymanoptera seek out sources of carbohydrates. Species that remain active during cold weather must store up enough of a carbohydrate reserve to make it through the winter. Honey Bees make honey for this purpose. As you are about to see, members of this suborder rely predominately upon pollen or insect prey for protein, and upon nectar and/or honeydew for carbohydrates.
We’ve assembled here a collection of images and some short commentary describing nearly two dozen kinds of Hymanoptera found in the Lower Susquehanna River Watershed, the majority photographed as they busily collected provisions during recent weeks. Let’s see what some of these fascinating hymanopterans are up to…
SOLITARY WASPS
A Great Black Wasp on goldenrod (Solidago species). Like other solitary wasps, a female Great Black Wasp will sting and paralyze a host insect upon which she’ll deposit her eggs. After hatching, the larvae will begin consuming the host’s body as a source of protein. The parasitized insects are often katydids or grasshoppers.A Great Black Wasp feeding on nectar, a source of carbohydrates. Unlike social bees and wasps, solitary wasps are equipped with a stinger solely used for immobilizing prey, not defending a nest. They are therefore quite docile and pose little threat to humans.A Great Black Wasp powdered with pollen. Hymanopterans that gather nectar and/or pollen are tremendously important pollinators of hundreds of species of plants.A female Thread-waisted wasp (Ammophilia species, probably A. nigricans) drags a paralyzed caterpillar to her excavated nest where she’ll deposit an egg on the body. After hatching, the larval wasp will feed on the disabled caterpillar. The protein will enable the larvae to grow, pupate, and later emerge as an adult wasp.The female Eastern Cicada Killer (Sphecius speciosus) excavates an underground nest with branch tunnels connecting a dozen chambers or more. As the common name suggests, the female wasp paralyzes a cicada, then makes a strenuous effort to fly and drag it back to the nest for placement in a cell. Each male wasp egg is deposited upon just one immobilized cicada, but a female egg is provided with a cache of several cicadas to provide adequate protein for growth to a larger size. Nest cells are sealed with soil, then the larvae hatch in just a couple of days. Within about two weeks, they have consumed the cicada protein and are fully grown. Wrapped in a cocoon, they spend the winter in the nest, then pupate in the spring before emerging as a new generation of adults.The Black-and-yellow Mud Dauber (Sceliphron caementarium) builds a mud-ball nest within which it packs paralyzed spiders to function as a source of protein for its larvae.A Black-and-yellow Mud Dauber at nest.The Pipe Organ Mud Dauber builds this elaborate nest in which their eggs and paralyzed spiders are deposited in cells sealed with mud partitions. After consuming the spiders, the larvae pupate, overwinter, then emerge from their cells as adults during the following spring. To escape the protection of the nest, the new generation of adults bore through the mud walls. Adult Pipe Organ Mud Daubers resemble the Great Black Wasp, but have a white or yellow distal segment on their rear legs resembling a pair of light-colored socks.A closeup of the previous image with the lengths of the nest tubes compressed to show four scavenger flies (Miltogramminae), possibly two species, that have invaded this Pipe Organ Mud Dauber nest. Scavenger flies are kleptoparasites that victimize various solitary bees and wasps, depositing larvae directly into the host species’ nest cells to consume the protein cache stored therein.
CUCKOO WASPS
Cuckoo Wasps (Chrysididae), also known as Emerald Wasps, parasitize the nests of other species of wasps. Females lay their eggs inside the host’s nest, then flee the scene. Upon hatching, larval Cuckoo Wasps feed on stockpiles of prey intended for the host species’ offspring. Like the adult mud daubers that have already matured and departed this nest by digging a hole through the wall of the cell within which they were hatched, the metallic green Cuckoo Wasp in the upper left has just emerged in much the same way.
SWEAT BEES
A Sweat Bee (Lasioglossum species) collecting nectar and pollen on White Snakeroot (Ageratina altissima).Sweat Bees (Lasioglossum species) visit human skin to lick up the electrolytes left behind by evaporating perspiration.Sweat Bees in the genus Lasioglossum demonstrate various social behaviors ranging from species that are solitary nesters to those that create colonies with work forces ranging in size from as few as four to as many as hundreds of bees. Some Lasioglossum practice kleptoparasitism, while others are quite accomplished foragers.A female Augochlorine Green Sweat Bee (Augochlorini) collecting nectar on White Snakeroot. Notice the pollen “baskets” on the rear leg.An Augochlorine Green Sweat Bee (Augochlorini). Sweat bees nest in subterranean cavities and in hollowed out sections of trees.A copper-colored Augochlorine Green Sweat Bee (Augochlorini) collecting nectar and dusted with pollen.
LEAFCUTTER AND MASON BEES
A Leafcutter Bee (Megachile species). Like Mason Bees, female Mason Bees deposit each of their eggs on a “pollen loaf” within an individual cell inside a preexisting tunnel-like cavity in wood, stone, or in the ground. Unlike Mason Bees, female Leafcutter Bees cut a circular piece of leaf to create each of the cells in their nest. After hatching, the larval bee feeds on the pollen loaf, pupates, then emerges from the shelter of the nest to start a new generation, usually during the following year.A Leafcutter Bee (Megachile species) visiting Wild Bergamot. Female Leafcutter and Mason Bees lack pollen “baskets” on their rear legs but instead have pollen “brushes” on the underside of the abdomen to gather the protein they need to create a “pollen loaf” for each nest cell.A Leafcutter Bee (Megachile species) collecting nectar from White Snakeroot.A Mason Bee (Osmia species) emerging from a nest in spring. Mason Bees create nesting cells within preexisting cavities in wood, stone, and other other supporting structures. Within the nest cavity, each egg is deposited atop a cache of pollen and nectar, a pollen loaf, then enclosed behind a partition of mud. The female Mason Bee will usually repeat this process until an entire cavity is filled with cells. During the following spring, a new generation of adult Mason Bees digs its way through the cell walls to emerge and repeat the process. These bees readily use paper straws or holes drilled in blocks of wood for nesting.A mason bee nest box with holes drilled into blocks of wood.Mason Bees seal each cell and the outer end of their nest cavity with mud. These outer nest cells can been parasitized by a variety of wasps. Here, the outer cell of a Mason Bee nest has been victimized by a tiny chalcid wasp (looks like another one to the lower left). Several species of female chalcid wasps (native Monodontomerus species or non-native Pteromalus venustus) enlarge weak points in the outer partition of a mason bee nest, then sting and paralyze the larval bee inside before depositing their eggs. Within the cell. the wasp larvae consume the larval Mason Bee and the “pollen loaf” provided for its growth. These same parasitic wasps prey upon Leafcutter Bees as well.
BUMBLE BEES, CARPENTER BEES, HONEY BEES, AND DIGGER BEES
A Common Eastern Bumble Bee (Bombus impatiens) collecting nectar and pollen on goldenrod. Bumble bees are our sole native group of social bees. Their wax nests are built in a burrow or other shelter. The eggs are deposited in cells along with a supply of pollen for nourishing the larvae upon hatching. Honey is stored in “honey pots” within the nest. New queens are produced along with male bees during the late-summer and fall. Only the new generation of fertilized queens survive the winter to lay eggs and produce workers to construct a new nest.A pair of Common Eastern Bumble Bees collecting nectar and becoming dusted with pollen. Their fuzzy coats and semi-warm-blooded metabolism allows them to be active in cooler weather than is tolerated by other bees.Flowering plants including the Great Rhododendron find success attracting pollinators to their reproductive blossoms by offering carbohydrate-rich nectar to insects like this Eastern Bumble Bee. The yellow spots on the flower’s upper petal help to guide visitors toward their sweet treat.An Eastern Carpenter Bee feeding on goldenrod nectar. Compare the almost hairless abdomen to that of the bumble bees. Carpenter bees are semi-social insects. Females lay their eggs in cells within galleries bored into wood. These nests are completed with great precision, avoiding creation of any second entrance by mistakenly breaching the outer surface of the excavated wood. Each egg/larvae is provided with a supply of protein-rich pollen. Males often hover outside their mate’s nest to prevent competing males from entering the area.A worker Honey Bee, a female member of a sisterhood of foragers from a nearby hive, visits goldenrod alongside Common Eastern Bumble Bees. Honey Bees were brought to North America during the 1620s, the earliest years of the trans-Atlantic migration of European colonists, to pollinate cultivated plants and to provide a reliable source of honey and beeswax. Within the Honey Bee’s social structure, the queen of each hive lays the eggs to produce the female worker bees. Once each year, male drones are produced along with a new generation of queens.In nature, Honey Bees build hives in tree cavities. Recently, this colony constructed a hive in a screech owl nest box at susquehannawildlife.net headquarters. To provide protein for the hatching larvae, worker bees collect pollen and deposit it within the hexagonal cells of the vertically aligned beeswax combs. After an egg is deposited upon the pollen cache, each cell is sealed with more beeswax. Young females tend these nest combs before maturing and becoming foraging worker bees.In apiculture, Honey Bees are raised in man-made hives. This Pennsylvania Association of Beekeepers display gives visitors to the Pennsylvania Farm Show in Harrisburg a look at the inner workings of a live bee hive. Nectar collected by worker bees is turned into honey to provide the supply of carbohydrates needed to fuel the colony through the winter. Note the honeycombs on the glass.A possible Small Carpenter Bee (Ceratina species) visiting White Snakeroot. Small Carpenter Bees nest inside hollow stems and twigs. Some species are eusocial, with a queen’s daughters and sisters sharing responsibility for finding food and rearing the young. Females overwinter inside a one of the excavated stems and begin a new nest there in the spring.A Digger Bee (possibly Melissodes species) with “pollen baskets” full of pollen collected from nearby flowers. Digger Bees in the genus Melissodes are often known as the Long-horned Bees. These social insects excavate underground nests and many species practice communal living.
SCOLIID WASPS
The Two-spotted Scoliid Wasp (Scolia dubia), also known as the Blue-winged Scoliid Wasp, is most frequently observed feeding on nectar. Scoliid wasps are solitary nesters, though they may assemble into groups while visiting flowers. They often ignore the presence of humans and are seldom disturbed by their presence. Females seek out the burrowing grubs of beetles including the Green June Bug (Cotinis nitida) and possibly the Japanese Beetle. After stinging a grub to paralyze it, the wasp will deposit her egg on its body, then bury it. Upon hatching, the larval wasp will feed on the grub for nourishment as it grows.Don’t like having your watermelon overrun by Green June Bugs while you’re eating? Then you ought to go out of your way to be nice to the Two-spotted Scoliid Wasp.The Double-banded Scoliid (Scolia bicincta) parasitizes beetle larvae as hosts for its larvae. For carbohydrates it relishes flower nectar.
PAPER WASPS
A Northern Paper Wasp (Polistes fuscatus). Paper wasps prey upon numerous garden pests, particularly caterpillars, to collect protein. Though they are social insects equipped with stingers to subdue their victims and defend their nests, paper wasps are surprisingly docile.A Northern Paper Wasp (Polistes fuscatus) feeding on nectar from a goldenrod flower.A Northern Paper Wasp harvesting wood pulp from the side of a mason bee nest box at susquehannawildlife.net headquarters. The pulp is chewed in the wasp’s saliva to create the paper used to construct the colony’s open-cell nest.Common Paper Wasps (Polistes exclamans), also known as Guinea Paper Wasps, at their open-cell nest. This and the nests of most other paper wasps are suspended on a filament or a pedicle. Many paper wasps can excrete an ant repellent on this section of the nest in an effort to prevent invasion. Like many other social hymenopterans, a defending wasp can secrete a pheromone venom during the stinging process to warn the colony of danger at the nest. In winter, Common Paper Wasps seek shelter in stumps and other locations to hibernate.The European Paper Wasp (Polistes dominula) is a non-native species which builds nests in man-made structures including bird houses. To collect protein, they prey on a wide selection of insects and other invertebrates. As such, European Paper Wasps are widespread and successful here in North America.
YELLOWJACKETS AND HORNETS
An Eastern Yellowjacket feeding on lanternfly honeydew. Eastern Yellowjackets derive much of their success from being generalists, collecting carbohydrates from nearly any sweet source, natural or man made. They are quite fond of ripe fruits, flower nectar, and sugary snacks and drinks, especially soda. Protein for nourishing their larvae is derived from the wide variety invertebrates upon which they prey and from carrion. These foods are chewed into a paste form in preparation for placement into the brood cells.A subterranean colony of Eastern Yellowjackets is started anew each spring by a young queen that has survived winter hibernation in diapause, a state of interrupted development. She constructs the new nest’s first cells using pulp made by chewing rotting wood. The first brood of workers scales up construction while the queen continues producing eggs. At the nest, these social insects will viciously attack anyone or anything perceived to be a threat, so give them their space and leave them alone. Many yellowjacket infestations of homes and other buildings are the work of non-native German Yellowjacket (Vespula germanica) [not shown], an invasive species that constructs paper nests in void spaces including walls and attics.Yellowjackets may be moody and aggressive, but they do fall victim to a number of predators. A Robber Fly (Promachus species) has taken down and is devouring this Eastern Yellowjacket.A Bald-faced Hornet (Dolichovespula maculata) feeding on Spotted Lanternfly honeydew on a Tree-of-heaven (Ailanthus altissima). In the absence of nectar-producing flowers, many bees, yellowjackets, and hornets have turned to the invasive lanternfly and Ailanthus combo to turn the sun’s energy into the carbohydrates they need. For protein, they prey upon spiders, flies, caterpillars, and a variety of other insects.To create paper for nest construction, this Bald-faced Hornet is collecting wood pulp from the surface of a weathered picnic table. Away from the nest, these hornets demonstrate a calm, carefree demeanor and can be closely observed.A Bald-faced Hornet nest in a pine tree. These hives are strictly temporary. Within the nest, a generation of drones (males) and new queens are produced late each year. These wasps leave the colony to mate. With the arrival of freezing weather, all inhabitants within the nest, including the old queen, perish, as do the drones that departed to breed. Only the new queens survive winter hibernation to propagate the next generation of wasps, starting with the workers needed to construct a fresh nest and reestablish the colony.Did you ever get the feeling you’re being watched? Don’t go messing around with Bald-faced Hornet nests. The occupants therein, like other social bees, wasps, and hornets, are equipped with stingers and venom for defending their colony. This is an adaptation that has developed over time to assure the survival of populations of these insects. Think about it this way, a solitary wasp that loses a nest loses only their individual brood of offspring. There is minimal impact on the wider local population of such insects. Conversely, a social wasp or hornet that loses a nest loses an entire colony, possibly negating the benefits of their cooperative behavior and threatening the survival of the species. Insects that cooperate to build societies for survival can be more vulnerable to the catastrophic impacts of certain circumstances like disease, weather, and invasion of their colonies. Therefore, natural selection has provided them with contingencies for these dangers, for example, the instinct to construct protective shelters and the adaptation of stingers and venom for defense against intruders and would-be predators. Oh, and by the way, the Bald-faced Hornet can spray venom, often aiming for the eyes, so keep your distance.European Hornets (Vespa crabro), an introduced species, are predatory on a variety of flying insects for protein. For carbohydrates they are attracted to sweets like this lanternfly honeydew on Tree-of-heaven.European Hornets constructing a paper nest in a tree cavity.
POTTER WASPS
A potter wasp (Eumenes species), probably a Fraternal Potter Wasp (E. fraternus), hovering near a European Paper Wasp on Partridge Pea. The female potter wasp builds a small mud nest resembling a tiny clay pot. One of her eggs is inserted and left hanging on a thin thread. Then a paralyzed caterpillar is deposited as a source of protein to nourish the larva upon hatching. Lastly, the pot is sealed with a lid made of wet mud. Upon maturing, the new generation of adult wasps perform a pottery breaking to emerge and take flight.
ANTS
Field Ants (Formica species, possibly Formica pallidefulva) clear the entrance to their underground nest. Field ants are eusocial insects, they work in concert to build, maintain, and defend the nest, rear young, and find food. There is no social caste system. Field Ants are predators and scavengers when collecting protein. For carbohydrates they often rely on the honeydew produced by aphids. As a method of improving and sustaining the production of honeydew, some ant species will tend colonies of aphids by moving the younger individuals from depleted portions of plants to more healthy tissue. Field Ant nests contain chambers used for a variety of functions including raising young and storing food. Some nests include multiple queens and some colonies consist of more than one nest. Ants in the genus Formica are weaponized; they can spray formic acid to repel intruders and defend their colony.
We hope this brief but fascinating look at some of our more common bees, wasps, hornets, and ants has provided the reader with an appreciation for the complexity with which their food webs and ecology have developed over time. It should be no great mystery why bees and other insects, particularly native species, are becoming scarce or absent in areas of the Lower Susquehanna River Watershed where the landscape is paved, hyper-cultivated, sprayed, mowed, and devoid of native vegetation, particularly nectar-producing plants. Late-summer and autumn can be an especially difficult time for hymanopterans seeking the sources of proteins and carbohydrates needed to complete preparations for next year’s generations of these valuable insects. An absence of these staples during this critical time of year quickly diminishes the diversity of species and begins to tear at the fabric of the food web. This degradation of a regional ecosystem can have unforeseen impacts that become increasingly widespread and in many cases permanent.
How can anyone be surprised by the absence of bees and other pollinators in farmland? Manicured and cultivated ground offers little in the way of year-round shelter and food sources for insects and other wildlife.This savanna-like habitat on a south-facing slope provides the abundance of nectar-producing, pollen-rich wildflowers needed to nourish a diverse population of insects including bees, wasps, hornets, and ants. Goldenrods, asters, and White Snakeroot are some of their late-season favorites.
Editor’s Note: No bees, wasp, hornets, or ants were harmed during this production. Neither was the editor swarmed, attacked, or stung. Remember, don’t panic, just observe.
SOURCES
Eaton, Eric R., and Kenn Kaufman. 2007. Kaufman Field Guide to Insects of North America. Houghton Mifflin Company. New York, NY.
Tropical Storm Ophelia has put the brakes on a bustling southbound exodus of the season’s final waves of Neotropical migrants. Winds from easterly directions have now beset the Mid-Atlantic States with gloomy skies, chilly temperatures, and periods of rain for an entire week. These conditions, which are less than favorable for undertaking flights of any significant distance, have compelled many birds to remain in place—grounded to conserve energy.
In the days prior to the arrival of Tropical Storm Ophelia, thousands of high-flying Broad-winged Hawks were being tallied as they passed hawk-counting stations throughout the region. As the last of this year’s migrants continue through, lack of clear skies, sunshine, and thermal updrafts has slowed the pace of their movements significantly.
Of the birds on layover, perhaps the most interesting find has been a western raptor that occurs only on rare occasions among the groups of Broad-winged Hawks seen at hawk watches each fall—a Swainson’s Hawk. Discovered as Tropical Storm Ophelia approached on September 21st, this juvenile bird has found refuge in coal country on a small farm in a picturesque valley between converging ridges in southern Northumberland County, Pennsylvania. Swainson’s Hawks are a gregarious species, often spending time outside of the nesting season in the company of others of their kind. Like Broad-winged Hawks, they frequently assemble into large groups while migrating.
A juvenile Swainson’s Hawk in Northumberland County, Pennsylvania.
Swainson’s Hawks nest in the grasslands, prairies, and deserts of western North America. Their autumn migration to wintering grounds in Argentina covers a distance of up to 6,000 miles. Among raptors, such mileage is outdone only by the Tundra Peregrine Falcon.
The Swainson’s Hawk spends up to four months each year covering a 12,000-mile round-trip migration route. The long primaries are an adaptation that give the wings additional lift, allowing them to use air currents including thermal updrafts to conserve energy while flying.
Swainson’s Hawks are renowned for spending time on the ground, intermittently running and hopping in pursuit of prey.
During the nesting cycle, Swainson’s Hawks consume primarily small vertebrates, mostly mice and other small rodents. But during the remainder of the year, they feed almost exclusively on grasshoppers. To provide enough energy to fuel their migrations, they must find and devour these insects by the hundreds. Not surprisingly, the Swainson’s Hawk is sometimes known as the Grasshopper Hawk or Locust Hawk, particularly in the areas of South America where they are common.
The juvenile Swainson’s Hawk visiting Northumberland County has been feeding on grasshoppers, katydids, and is seen here eating a cricket.
So just how far will our wayward Swainson’s Hawk have to travel to get back on track? Small numbers of Swainson’s Hawks pass the winter in southern Florida each year and still others are found in and near the scrublands of the Lower Rio Grande Valley in Texas and Mexico. But the vast majority of these birds make the trip all the way to the southern half of South America and the farmlands and savannas of Argentina—where our winter is their summer. The best bet for this bird would be to get hooked up with some of the season’s last Broad-winged Hawks when they start flying in coming days, then join them as they head toward Houston, Texas, to make the southward turn down the coast of the Gulf of Mexico into Central America and Amazonia. Then again, it may need to find its own way to warmer climes. Upon reaching at least the Gulf Coastal Plain, our visitor stands a much better chance of surviving the winter.
As long as it can still find grasshoppers to eat, our wayward bird in Northumberland County still has time before it needs to make its way south. As they pass through Texas, Mexico, Costa Rica, and Panama, Swainson’s Hawks are numerous among flocks of southbound Broad-winged Hawks. But while hawk watches in these areas are presently recording maximum annual counts of the latter, peak numbers of the former won’t occur until the final two or three weeks of October.
They look amazingly similar to the green leaves on a deciduous tree. During the late summer and autumn, they spend their time as adults in the cover of the forest canopy. They prefer to run and hop rather than fly. But despite their discretion, you’re not likely to miss the Common True Katydid (Pterophylla camellifolia).
The Common True Katydid, also known as the Northern True Katydid, has no trouble at all hiding among the leaves.
Take a listen and you may hear the male’s nocturnal calls filling the treetops of woodlands and shady neighborhoods throughout the lower Susquehanna valley right now. The loud, raspy “ka-ty-did, she-did, she-didn’t” is reliably answered by other nearby males as competition for willing females reaches a frenzy. In mature forests where populations are dense, this rowdy chorus can reach a remarkable volume.
A mated female Common True Katydid inserts her ovipositor into a timber crevice to place her eggs in a protected location for winter.
The Common True Katydid’s song is like a soundtrack for the oft times melancholy mood of autumn. As the days shorten and a chill fills the air, the rate of the Common True Katydid’s call becomes slower and its tone deeper in response to the falling temperatures. Males continue forcing a sluggish call until freezing conditions finally bring about their demise. Another generation and another season gone.
Grasshoppers are perhaps best known for the occasions throughout history when an enormous congregation of these insects—a “plague of locusts”—would assemble and rove a region to feed. These swarms, which sometimes covered tens of thousands of square miles or more, often decimated crops, darkened the sky, and, on occasion, resulted in catastrophic famine among human settlements in various parts of the world.
The largest “plague of locusts” in the United States occurred during the mid-1870s in the Great Plains. The Rocky Mountain Locust (Melanoplus spretus), a grasshopper of prairies in the American west, had a range that extended east into New England, possibly settling there on lands cleared for farming. Rocky Mountain Locusts, aside from their native habitat on grasslands, apparently thrived on fields planted with warm-season crops. Like most grasshoppers, they fed and developed most vigorously during periods of dry, hot weather. With plenty of vegetative matter to consume during periods of scorching temperatures, the stage was set for populations of these insects to explode in agricultural areas, then take wing in search of more forage. Plagues struck parts of northern New England as early as the mid-1700s and were numerous in various states in the Great Plains through the middle of the 1800s. The big ones hit between 1873 and 1877 when swarms numbering as many as trillions of grasshoppers did $200 million in crop damage and caused a famine so severe that many farmers abandoned the westward migration. To prevent recurrent outbreaks of locust plagues and famine, experts suggested planting more cool-season grains like winter wheat, a crop which could mature and be harvested before the grasshoppers had a chance to cause any significant damage. In the years that followed, and as prairies gave way to the expansive agricultural lands that presently cover most of the Rocky Mountain Locust’s former range, the grasshopper began to disappear. By the early years of the twentieth century, the species was extinct. No one was quite certain why, and the precise cause is still a topic of debate to this day. Conversion of nearly all of its native habitat to cropland and grazing acreage seems to be the most likely culprit.
The critically endangered Eskimo Curlew (Numenius borealis), a species not photographed since 1962 and not confirmed since 1963, fed on Rocky Mountain Locusts during its spring migration through the Great Plains. Excessive hunting and conversion of grasslands to agriculture are believed responsible for the bird’s demise. (United States Fish and Wildlife Service image by Christina Nelson)
In the Mid-Atlantic States, the mosaic of the landscape—farmland interspersed with a mix of forest and disturbed urban/suburban lots—prevents grasshoppers from reaching the densities from which swarms arise. In the years since the implementation of “Green Revolution” farming practices, numbers of grasshoppers in our region have declined. Systemic insecticides including neonicotinoids keep grasshoppers and other insects from munching on warm-season crops like corn and soybeans. And herbicides including 2,4-D (2,4-Dichlorophenoxyacetic acid) have, in effect, become the equivalent of insecticides, eliminating broadleaf food plants from the pasturelands and hayfields where grasshoppers once fed and reproduced in abundance. As a result, few of the approximately three dozen species of grasshoppers with ranges that include the Lower Susquehanna River Watershed are common here. Those that still thrive are largely adapted to roadsides, waste ground, and small clearings where native and some non-native plants make up their diet.
Here’s a look at four species of grasshoppers you’re likely to find in disturbed habitats throughout our region. Each remains common in relatively pesticide-free spaces with stands of dense grasses and broadleaf plants nearby.
CAROLINA GRASSHOPPER
Dissosteira carolina
The Carolina Grasshopper, also known as the Carolina Locust or Quaker, is one of the band-winged grasshoppers. It is commonly found along roadsides and on other bare ground near stands of tall grass and broadleaf plants.The Carolina Grasshopper is variable in color, ranging from very dark brown……to a rich tan or khaki shade. These earth-tone colors provide the insect with effective camouflage while spending time on the ground.The Carolina Grasshopper is most readily detected and identified when it flies. The colors of the wings resemble those of the Mourning Cloak butterfly.Carolina Grasshoppers are among the preferred victims of Great Black Wasps (Sphex pensylvanicus). A female wasp stings the grasshopper to paralyze it, then drags it away to one of numerous cells in an underground burrow where she lays an egg on it. The body of the disabled grasshopper then provides nourishment for the larval wasp.
DIFFERENTIAL GRASSHOPPER
Melanoplus differentialis
Differential Grasshopper nymph with small “fairy wings”.An adult female Differential Grasshopper with fully developed wings.An adult female Differential Grasshopper
TWO-STRIPED GRASSHOPPER
Melanoplus bivittatus
An early-stage Two-striped Grasshopper nymph.A Two-striped Grasshopper nymph in a later stage.An adult female Two-striped Grasshopper.An adult female Two-striped Grasshopper. Note the pale stripe originating at each eye and joining near the posterior end of the wings to form a V-shaped pattern.An adult female Two-striped Grasshopper.
RED-LEGGED GRASSHOPPER
Melanoplus femurrubrum
An adult male Red-legged Grasshopper hiding in dense urban vegetation.The Red-legged Grasshopper may currently be our most abundant and widespread species.An adult male Red-legged Grasshopper.An adult female Red-legged Grasshopper.
Protein-rich grasshoppers are an important late-summer, early-fall food source for birds. The absence of these insects has forced many species of breeding birds to abandon farmland or, in some cases, disappear altogether.
Beginning in the early 1930s, the Western Cattle Egret (Bubulcus ibis), a notoriously nomadic species, transited the Atlantic from Africa to colonize the Americas…and they did it without any direct assistance from humans. During the 1970s and early 1980s, a nesting population of Western Cattle Egrets on river islands adjacent to the Susquehanna’s Conejohela Flats off Washington Boro was the largest inland rookery in the northeastern United States. The Lancaster County Bird Club censused the birds each August and found peak numbers in 1981 (7,580). During their years of abundance, V-shaped flocks of cattle egrets from the rookery islands ventured into grazing lands throughout portions of Lancaster, York, Dauphin, and Lebanon Counties to hunt grasshoppers. These daily flights were a familiar summertime sight for nearly two decades. Then, in the early 1980s, reductions in pastureland acreage and plummeting grasshopper numbers quickly took their toll. By 1988, the rookery was abandoned. The cattle egrets had moved on. (Vintage 33 mm image)During the summer and early fall, juvenile and adult Ring-necked Pheasants feed heavily on grasshoppers. Earlier and more frequent mowing along with declining numbers of grasshoppers on farmlands due to an increase in pesticide use were factors contributing to the crash of the pheasant population in the early 1980s.To the delight of Wild Turkeys, each of the four species of grasshoppers shown above frequents clearings and roadsides adjacent to forest areas. While changes in grasshopper distribution have been detrimental to populations of birds like pheasants, they’ve created a feeding bonanza for turkeys.Wild Turkeys feeding on an abundance of grasshoppers along a forest road.An American Kestrel feeds on a grasshopper while ignoring the abundance of Spotted Lanternflies swarming the adjacent utility pole. In Susquehanna valley farmlands, grasshopper and kestrel numbers are down. Lanternflies, on the other hand, have got it made.Maintaining areas bordering roads, forests, wetlands, farmlands, and human development in a state of early succession can provide and ideal mix of mature grasses and broadleaf plants for grasshoppers, pollinators, birds, and other wildlife.
The calls of Fall Field Crickets, a series of chirps one might attempt to replicate by quickly strumming three to five teeth on a hair comb, are a familiar chorus during the late summer and autumn in the Lower Susquehanna River Watershed. The song’s speed changes with temperature, becoming noticeably slower as cold weather sets in. These crickets sing throughout the majority of the day and night, becoming quietest during the chilly hours of dawn. Adults hide in burrows and beneath logs, leaf litter, and other organic debris. Around human habitation, they seek shelter under hundreds of different objects, frequently finding their way into buildings where they do no real harm. Crickets are eaten by almost every predator that exceeds them in size and are especially important as a protein-rich food source for birds feeding their young and preparing for autumn migration. The Fall Field Cricket (Gryllus pennsylvanicus) is nearly identical in appearance to the less common Spring Field Cricket (Gryllus veletis), which calls during the spring and early summer in the Susquehanna valley. The primary difference between the two species? The former overwinter as eggs while the latter pass the colder months as nymphs.
The Gray Comma is a strikingly colorful late-summer butterfly of rich forests in the Lower Susquehanna River Watershed. It’s sure to catch your attention,……or is it?
Check out this and other local species by clicking the “Butterflies” tab at the top of this page.
To pass the afternoon, we sat quietly along the edge of a pond created recently by North American Beavers (Castor canadensis). They first constructed their dam on this small stream about five years ago. Since then, a flourishing wetland has become established. Have a look.
Vegetation surrounding the inundated floodplain helps sequester nutrients and sediments to purify the water while also providing excellent wildlife habitat.The beaver lodge was built among shrubs growing in shallow water in the middle of the pond.Woolgrass (Scirpus cyperinus) is a bulrush that thrives as an emergent and as a terrestrial plant in moist soils bordering the pond.A male Common Whitetail dragonfly keeping watch over his territory.A Twelve-spotted Skimmer perched on Soft Rush.A Blue Dasher dragonfly seizing a Fall Field Cricket (Gryllus pennsylvanicus).A Spicebush Swallowtail visiting a Cardinal Flower.A Green Heron looking for small fish, crayfish, frogs, and tadpoles.The Green Heron stalking potential prey.A Wood Duck feeding on the tiny floating plant known as Lesser Duckweed (Lemna minor).A Least Sandpiper poking at small invertebrates along the muddy edge of the beaver pond.A Solitary Sandpiper.A Solitary Sandpiper testing the waters for proper feeding depth.A Pectoral Sandpiper searches for its next morsel of sustenance.The Sora (Porzana carolina) is a seldom seen rail of marshlands including those created by North American Beavers. Common Cattails, sedges, and rushes provide these chicken-shaped wetland birds with nesting and loafing cover.
Isn’t that amazing? North American Beavers build and maintain what human engineers struggle to master—dams and ponds that reduce pollution, allow fish passage, and support self-sustaining ecosystems. Want to clean up the streams and floodplains of your local watershed? Let the beavers do the job!
At first glance, this insect might be mistaken for a Brown Marmorated Stink Bug. It is, however, a native species, a Magnolia Leaf-footed Bug (Leptoglossus fulvicornis). Because it feeds almost exclusively on trees in the genus Magnolia, and because the three members of the genus native to the lower Susquehanna valley, Umbrella Magnolia (M. tripetala), Cucumber Tree (M. acuminata), and Sweetbay (M. virginiana), each have a very limited distribution here, this insect’s presence in the watershed is largely dependent on widespread introductions of ornamental magnolias and native transplants including Southern Magnolia (Magnolia grandiflora). Adult Magnolia Leaf-footed Bugs overwinter in leaf litter beneath the host trees. In spring, females lay their eggs in rows along the midrib of the leaves where they are often victims of parasitoid wasps including Gyron pennsylvanicum. The surviving nymphs and the adults feed on the tree’s leaves and fruits, causing little harm to its overall health.
The Broad-necked Root Borer (Prionus laticollis) is one of the Lower Susquehanna River Watershed’s largest insects. Its larvae feed on woody roots for more than two years before pupating and thereafter emerging as adult beetles. The distribution of root borers is not totally random. They are often attracted to distressed trees and shrubs. This particular specimen was found along a forest road where herbicide application, soil dehydration, and a recent wildfire has weakened and killed numerous oaks, poplars, and maples. As they feed, root borer larvae will help begin the process of reducing the remains of these trees into soil nutrients that will benefit regeneration of forest plants at this site.
Looking for a native wildflower that’s tall, showy, and a great choice for attracting wildlife, especially butterflies and bees? Then check out Wild Senna (Senna hebecarpa).
Wild Senna currently blooming in a roadside wildflower garden on Pennsylvania State Game Lands.
Wild Senna, also known as American Senna, is a host plant for the larvae of Cloudless Sulphur and Sleepy Orange (Eurema nicippe) butterflies. It thrives in almost any moist, well-drained soil in habitats including open woodlands, forest edges, meadows, and gardens like yours. Its height at flowering ranges from three to six feet. If you prefer, this perennial wildflower can even be cultivated as a shrub-like form. It is easily grown from seed, which is available from Ernst Conservation Seeds of Meadville, Pennsylvania, as well as numerous other vendors. And don’t forget to give Wild Senna’s two close relatives, Partridge Pea and Maryland Senna, a try as well. They attract the same species of butterflies and are just as easy to grow. You’ll like ’em.
Cloudless Sulphur butterflies from populations in the south colonize the Lower Susquehanna River Watershed each summer in varying numbers.Close-up view of a Wild Senna flower cluster. Typical of members of the pea family, the seeds of all native Senna species develop within pods after blooming and are sought after by wildfowl (Galliformes), particularly Northern Bobwhite.Partridge Pea with flowers and seed pods in the susquehannawildlife.net garden. Smaller than the other Senna species, Partridge Pea reaches a height of just two to three feet.
Your best bet for finding migrating shorebirds in the lower Susquehanna region is certainly a visit to a sandbar or mudflat in the river. The Conejohela Flats off Washington Boro just south of Columbia is a renowned location. Some man-made lakes including the one at Middle Creek Wildlife Management Area are purposely drawn down during the weeks of fall migration to provide exposed mud and silt for feeding and resting sandpipers and plovers. But with the Susquehanna running high due to recent rains and the cost of fuel trending high as well, maybe you want to stay closer to home to do your observing.
Fortunately for us, migratory shorebirds will drop in on almost any biologically active pool of shallow water and mud that they happen to find. This includes flooded portions of fields, construction sites, and especially stormwater retention basins. We stopped by a new basin just west of Hershey, Pennsylvania, and found more than two dozen shorebirds feeding and loafing there. We took each of these photographs from the sidewalk paralleling the south shore of the pool, thus never flushing or disturbing a single bird.
Designed to prevent stream flooding and pollution, this recently installed stormwater retention basin along US 322 west of Hershey, Pennsylvania, has already attracted a variety of migrating plovers and sandpipers.Killdeer stick close to exposed mud as they feed.Two of more than a dozen Least Sandpipers found busily feeding in the inch-deep water.A Lesser Yellowlegs searching for small invertebrates.Two Lesser Yellowlegs work out a disagreement.Male Twelve-spotted Skimmers patrol the airspace above a pair of Least Sandpipers. Dragonflies and other aquatic insects are quick to colonize the waters held in well-engineered retention basins. Proper construction and establishment of a functioning food chain/web in these man-made wetlands prevents them from becoming merely temporary cesspools for breeding mosquitos.
So don’t just drive by those big puddles, stop and have a look. You never know what you might find.
A Semipalmated Sandpiper (middle right) joins a flock of Least Sandpipers.Pectoral Sandpipers (two birds in the center) are regular fall migrants on the Susquehanna at this time of year. They are most frequently seen on gravel and sand bars adjacent to the river’s grassy islands, but unusually high water for this time of year prevents them from using this favored habitat. As a result, you might be lucky enough to discover Pectoral Sandpipers on almost any mudflat in the area.Two Pectoral Sandpipers and five smaller, but otherwise very similar, Least Sandpipers.A Killdeer (right), a Semipalmated Plover (upper right), and Least and Pectoral Sandpipers (left).
An ever-vigilant male Blue Dasher (Pachydiplax longipennis) perches on a small twig overlooking the vegetated shallows along the shoreline of Memorial Lake in Lebanon County, Pennsylvania.
